Well flow device



Dec. 25, 1945. R. o. wALToN WELL FLOW DEVICE Filed Oct. 2l, 1944 Patented Dec. 25, 1945 2,391,605 WELL FLow DEvIcE Robert 0. Walton, Dallas, Tex., assigner to Merla Tool Corporation, Dallas, Tex., a corporation of Texas Application October 21, 1944, Serial No. '559,710

11 Claims.

This invention relates to new and useful improvements in well flow devices.

The invention is a modiiication of and improvement on the device shown in my co-pending applications, Serial No. 451,570, led July 20, 1942, and Serial No. 539,424, filed June 9, 1944, patented September 18, 1945, No. 2,385,316. y One object of the invention is to provide an improved device for controlling the admission of a lifting fluid, such as gas, into a liquid column within a well tubing or conductor for lifting or raising the liquid within a well tubingor conductor to the surface, said device being particularly adapted for use as an intermitter to lintermittently admit the lifting gas at predetermined intervals in accordance with well conditions.

An important object of the invention is to provide an improved well flow device having all of the advantages of the devices disclosed in my copending applications, above referred to, and in addition having an improved main valve element which forms substantially no appreciable obstruction to the flow past the element when said element is in an open position and which is constructed so that a straight line flow past the valve element is possible; said element also being arranged to assure the maintenance of a positive seal even though said element may become Worn by the abrasive action of the fluid owing past the element.

A particular object of the invention is to provide an improved well flow device having a main valve element for controlling the admission of a lifting fluid into a well tubing, said valve element being constructed of a flexible sleeve-like or tubular member which is adapted to be moved to open and closed positions by the pressures acting exteriorly and interiorly thereof; the flexibility of said member assuring positive sealing when in a closed position and also permitting the member to form substantially no restriction to the ow when said member is in an open position.

Another object of the invention is to provide an improved main valve element for a well ow device comprising an elongate tubular member having one end closed, said member being adapt.. ed to close the flow through the device when in an expanded position and to open said flow when in a collapsed position; the pressure interiorly and exteriorly of the tubular member being normally equalized and there being means, either the inherent resiliency of the member or an auxiliary resilient means, for maintaining the member expanded in its closed position during such equalization of pressures. The valve device including pilot valve means for releasing the pressure acting within the interior of said member, whereby the external pressure may function to collapse the member and thereby move it to its open position.

Still another object oi the invention is to provide an improved well ow device having a simplied one-piece main valve whereby the device comprises a minimum number of parts and may be manufactured 'at a minimum cost.

The construction designed to carry out the invention will be hereinafter described together with other features of the invention.

The invention will be more readily understood from a reading of the following specification and by reference to the accompanying drawing, wherein an example of the invention is shown, and wherein:

Figure l is a view, partly in section and partly in elevation of a well bore having a well tubing extending therethrough and showing a plurality of well devices, constructed in accordance with the invention, mounted in the tubing,

Figure 2 is -an enlarged transverse, vertical sectional view of the flow device with the main valve and pilot valve closed,

Figure 3 is a view, similar to Figure 2 of the lower portion of the valve device with the main valve open, and,

Figure 4 is a horizontal, cross-sectional view, taken on the line 4-4 of Figure 2.

In the drawing, the letter A designates a well bore having a well casing Ill therein. A well tubing II extends downwardly through the casing Ill and has its upper end supported in the usual casing head I2 which is mounted on the upper end of said casing. The lower end of the well tubing has the conventional well screen I3 through which the well uids are admitted into said tubing attached thereto. A suitable well packer I4 which is schematically illustrated packs off between the tubing and casingabove the perforated screen I3.

A plurality of valve devices B, constructed in accordance with the invention, are connected in the tubing II and are located at various elevations or levels therein. As will be hereinafter described, each device B is adapted to control the admission of a lifting fluid, such as gas, into the well tubing string and such fluid is utilized to lift the well liquids upwardly through said tubing to the surface. The invention will be herein described as operating with an Aauxiliary lifting duid, such as gas, but it is noted that the lifting fluid may be gas from a sub-surface forma-r tion which is conducted into the well casing. when auxiliary lifting iiuid is employed, said lifting fluid or gas is conducted to the annular space between the well casing III and the well tubing through an inlet pipe I5 which is connected to the casing head I2, the admission of said gas being controlled by a time-controlled intermitting device I6. The time-controlled intermitter IE, as is well known, controls the admission of gas to admit the same in predetermined volumes at desired intervals and said device is adjusted in accordance with the particular conditions of each well.

The devices B are all of identical construction and each device includes a tubular housing which is constructed of three sections, an upper section I1, an intermediate section I8 and a lower section I9; the sections I8 and I9 are connected together by a coupling Ia. The section I9 is formed with an axial bore 20 and the lower end of this bore is closed by an integral bottom 2I. The bottom 2I of the section I9 is provided with a plurality of admission ports 22 which communicate with an angular nipple 23 to which the lower end of the section I9 is attached. The nipple is suitably connected with the well tubing I0 and obviouslyI its upper portion and it is apparent that fluid may flow from the annular space through the openings 24, admission ports 22 and nipple 23 into the tubing. The combined cross-sectional area of the inlets 24 is greater than the combined cross-sectional area of the Yadmission ports 22 whereby fluid from the casing Il) may enter the section I9 more rapidly than it can escape therefrom through the ports 22.

The coupling I8a which connects the sections I8 and I9 has an axial bore 25 extending therethrough and this bore forms a counterbore to the main bore 20 of the section I9. The -bore 25 has communication with the annular space between the well casing Ill and tubing II through a radially extending reduced passage 26, whereby pressure .present within the well casing may enter the bore. The upper end of the bore 25 is normally closed by a pilot valve 21 which will be hereinafter described in detail; when the pilot valve is closed the pressure is trapped within the bore 25 and opening of said valve will permit escape of this pressure.

For controlling the flow of fluid into the section I9 and thence to the well tubing through the admissionports 22, a flexible Valve element 28 is disposed within the section I9. The element 28 is constructed of neoprene, or other synthetic or plastic composition, or of a suitable rubber compound and is generally tubular in cross-section with its lower end closed by an integral bottom 29 which is preferably rounded. The open upper end of the element is engaged over and secured to a depending collar 30 which is formed integral with the coupling I8a. It is obvious that with this arrangement the interior of the element 28 is exposed to the pressure present within the well casing exteriorly of the device B through the bore 25 and reduced passage 26 of the coupling I8a, while the outer surface of the element is exposed to this same pressure through the inlet openings 24.

With the pilot valve 21 vclosed to trap the pressure withln/ the bore 25, the pressures acting interiorly and exteriorly on the element are equallzed and the normal elasticity or resiliency of said element will hold the same expanded to the position shown in Figure 2. In such position the outer surface of the element engages the inner wall of the section I9 to seal off thereagainst and close the inlet openings 24. In order to assure a tight seal with said inner wall, annular irregularities or corrugations 3l may be formed on said wall below the inlets 24 and the flexible surface of the element will conform to the corrugations to effect a positive sealing action. Thus, when the pilot valve 21 is closed and equal pressures are acting exteriorly and interiorly of the valve element, said element is in an expanded position to close the inlet openings 24 and prevent flow from the well casing I0 into the tubing.

When the pilot valve 21 is opened, as will be explained, the pressure may escape from the bore 25 and the pressure acting on the interior of the valve element 28 is immediately reduced; as soon as this occurs the pressure acting exteriorly on said element collapses or distorts the element inwardly as shown in Figure 3, whereby the element is moved away from the'inner wall of the section I9 to uncover the ports 24 and thereby permit a flow of fluid from the well casing I0, through ports 24, admission ports 22 and nipple 23 into the well tubing. Since the element is of flexible material, it is apparent that said element will readily distort out of the main line of ow and will form substantially no restriction or impedance to said ilow. The valve element will remain in its distorted or open position until the pilot Valve 21 again closes to trap the pressure acting within the element to again equalize the pressures interiorly and exteriorly thereof and thereby allow the element to return to an expanded position closing the inlet openings 24.

It may be that the inherent resiliency or flexibility of the element 28 is insuiiicient to assure positive sealing and it may be desirable to provide auxiliary means for expanding the element when the pressures thereacross are equal. In such instance, arcuate expanding shoes or plates 32 may be disposed within the element on diametrically opposite sides thereof. Each shoe or plate has a projecting stud 33 secured thereto and a coiled spring 34 having its ends surrounding said studs is located between the shoes and constantly urges said shoes outwardly of each other. It is preferable that the expanding shoes or plates be disposed in the same plane as the corrugations 3| on the wall of the section I9 to assure sealing at this point. When the pressures acting interiorly and exteriorly of the element are equal the coiled spring 34 will assure expansion of the element into sealing engagement with the inner wall of the section I9 to close the inlets 24. Reduction of the pressure within the element will allow the external pressure to overcome the tension of the spring 34 to collapse the element as shown in Figure 3. The use of the expanding shoes 32 and spring 34 is optional and when the inherent elasticity of the element 28 is sufficient to effect sealing when pressures across the element are equalized, these parts may be omitted.

As explained, the pilot valve 21 controls the escape of pressure from within the interior of the valve element 28 since said pilot controls flow from the upper end of the bore 25 of the coupling I8a. When the pilot 21 is lifted to an open position a flow from the bore 25 into the bore 35 of the intravel of the pilot valve.

termediate section I8 of the device may occur. The interior of the intermediate section I8 ccmmunicates with the well tubing through a tubular nipple 38 which ispreferably made integral with the section and which has its outer end suitably connected within a radial opening 31 in the well tubing string. Thus, when the pilot valve 21 is opened the pressure acting within the interior of the element 28 escapes from the upper end of the bore 25 into the bore 35 ofthe section I8, from where it flows into the well tubing I0. It is noted that the size of the bore of the tubular nipple 38 which provides an escape port is considerably larger than the diameter of the inlet passage 28 through which pressure enters the bore 26 and therefore when the pilot valve is vopened the pressure from within the element 28 escapes more rapidly through the nipple 38 than it can be replenished through the reduced passage 26. This results in a definite reduction of pressure within the element thereby permitting the external pressure to distort the element inwardly to an open position, as has been explained.

The lifting fluid or gas is present within the well casing I0 exteriorly of the tubing and it is apparent that said lifting fluid pressure is acting on the main valve element 28. When the main valve element is opened the lifting fluid is admitted into the well tubing I0 to lift the liquid column therein and it is desirable that the pressure of the lifting gas be sufficiently high to efiiclently lift said liquid. Since the pilot valve 21 controls the opening of the main valve it is necessary that said pilot valve remain closed to hold the element 28 in closed position until the pres.. sure of the lifting gas within the well casing I 0 reaches a predetermined point. y

In order to open the pilot valve 21 when the pressure of the lifting fluid reaches the predetermined desired point, said valve is actuated solely by the lifting fluid pressure. As is clearly shown in Figures 2 and 3, the pilot valve includes a stem 3B which extends upwardly through a reduced counterbore 39 formed in the lower portion of the upper section I1. A suitable packing ring 40 is disposed within a recess 4Ilin the counterbore and surrounds the stem to seal oil around said stem. Theupperend of the stem extends upwardly into the main bore 42 of the section I1 and has its extreme upper end fastened to a plug 43. The plug 43 is attached to and closes the lower end of an operating bellows 44 which is disposed within the upper portion of the section I1. The upper end of the bellows is fastened to a depending collar 45 which is formed integral with a cap member 46, the latter being mounted in position between the upper end of the section I1 and a closure t1 having threaded connection with said section.

The bellows 44 is constructed so that its normal spring action tends to expand the bellows whereby the pilot valve attached to its lower end is normally urged toward its seated position.

The interior of the bellows is filled (Figure 2) with a suitable fluid such as water or oil and the upper end of said bellows communicates with a recess 48 in the cap member 48. When the bellows is expanded and the pilot valve seated (Figure 2) the fluid does not completely flll the recess, whereby the bellows may be depressed until this recess is -completely filled. The volume of uid within the bellows will determine the amount of movement which the bellows may undergo and thus the fluid acts as a positive stop to limit the Also, it is apparent that 'device be set for the highest pressure.

when the bellows is fully depressed the fluid completely fills said bellows and recess and since said fluid is nonfcompressible. rupturing or breaking of the bellows by an' excessive external pressure on said bellows cannot occur. Thus, the fluid not only acts as a stop for limiting movement' of the pilot valve but also acts to prevent rupturing of said bellows by external pressure and this is an important feature of the invention.

In addition to the normal 'action of the bellows urging the pilot valve to its seated position, a coiled spring 48a surrounds the pilot valve stem 38 within the upper section I1. 'I'his spring has its lower end engaging an external annular flange or ring 49 which is secured to the stem, while its upper end is confined against the lower end of a fixed sleeve 50. The sleeve 50 has its upper end fastened to the cap member 46 and encircles the pilot bellows 44. The plug 43 which closes the lower end of the bellows vand has the stem attached thereto is arranged to engage the flanged lower end of the sleeve when the pilot valve is in a lowered or closed position (Figure 2). The sleeve 50 has a plurality of ports or openings 5I therein while the upper s'ection is provided with inlet ports 52 whereby the pressure of the lifting fluid in the casing may enter the section and then the sleeve to act upon the bellows 44 to depress the same. It is noted that the sleeve 50 could be replaced by elongate stop arms which would serve the same purpose.

The spring 48a which urges the pilot valve to its closed position is of a predetermined tension and obviously, the pressure of the lifting fluid acting against the pilot bellows 44 must reach a predetermined pressure before the pilot valve will open. By changing the tension of this spring, the pilot valve may be arranged to open at any desired lifting fluid pressure. No differential of pressure across the valve is depended upon because the spring exerts a constant ilxed pressure on the valve which can be overcome only when the lifting fluid pressure exceeds such constant.

In operation, a plurality of valve devices B are connected in the tubing stringII and are disposed at various elevations therein. Each valve device has its lspring 48a properly adjusted so as to exert a predetermined pressure upon its pilot valve 33, it being preferable that the uppermost For eX- ampie, the uppermost valve device in the tubingmay be set to open the pilot valve at 450 pounds vper square inch, the next set to open at 425 pounds, the third at 400 and so on progressively to the lowermost device in the tubing which would, of course, be operated by the lowest pressure. f

Normally, each valve device has its parts in the position shown in Figure 2 with the main valve element 2B in its expanded or closed position and the pilot valve 21 closed. After the well liquid within the casing outside the tubing and above the packer I4 has been replaced by the lifting fluid, the pressure of said lifting fluid is maintained at a point below that at which the lowermost valve is set to operate. Thus, a lifting fluid pressure is normally maintained within the well casing but such pressure is insuilicient to actuate the valve devices. At this time, the apparatus is ready for operation to control the admission of lifting fluid from the well casing I0 into the well tubing and through the lowermost valve.

The lifting fluid pressure which is present in the well casing is acting on the interior of the valve element 28 through the passage 28 and bore 25 and is also acting exteriorly of said element through the ports 24 so that the pressures exteriorly and interiorly of the element are equalized. The inherent resiliency of the materialof which the element is constructed, or the pressure of the coiled spring 34 if said spring and expanding shoes 32 are employed, maintain saidv element in its expanded or closed position. The lifting fluid pressure within the casing l is also acting against the pilot valve 21 through bore 25 as well as against the exterior of the pilot bellows 44 through ports 52 in the section I1 and ports 5l in the sleeve 50; however, at this time the lifting fluid pressure is insufficient to open the pilot valve 21 against the resistance of the spring 48a What I claim and desire to secure by Letters Patent is:

1. A flow device including, a well tubing, a housing adapted to be connected in said well tubing and having a now passage for establishing communication between 'the exterior and interior of the well tubing, a main valve element for controlling the flow through said passage, said elei ment comprising a hollow member constructed and bellows 44 which are holding said valve in seated or closed position.

The liquid column in the well tubing is permitted to build up to its standing level after which the intermitter i6 actuated to admit a charge of lifting fluid into the well casing to increase the pressure of the lifting fluid within the well casing i0. As this pressure reaches the point at which the lowermost valve is set said pressure acting on the pilot bellows 44 overcomes the resistance of the spring 48a and depresses said bellows to cause upward movement of the pilot valve 21 from its seat. As soon as this occurs the pressure within the main valve element 28 may escape upwardly through the bore and nipple 36 into the tubing (Figure 3) with the result that the pressure within the element is reduced. The lifting fluid pressure within the casing I0 which is acting on the exterior of the element is substantially constant and immediately upon the reduction of pressure within the element this pressure will distort said element inwardly to the position shown in Figure 3, whereby the inlets 24 are uncovered and a lifting fluid flow through the section I9 and angular nipple 23 into the well tubing may occur. The admitted lifting fluid will lift the well liquid within the tubing in the usual manner. The main valve element will remain in its distorted or collapsed position as long as the pressure acting upon the pilot bellows 44 is sufficient to hold the pilot valve 21 o-pen. However, when the lifting fluid pressure falls below the pressure necessary to maintain the pilot open, the pilot valve closes to again trap the pressure within the element and permit equalization of the pressures exteriorly and interiorly of said element to cause said element to return to its expanded position closing the inlets 24.

As has been explained, the combined cross-sectional area of the inlets 24 is greater than the cross-sectional area of the admission ports 22, whereby the pressure is not rapidly dissipated within the section I9 when flow through the ports 22 occuis. This assures Vthat the element 22 will be held in a distorted or collapsed position until such time as the pilot valve closes. Since the element 28 is constructed of a yieldable material. it will be moved out of the line of flow and will form substantially no restriction to the flowing fluid; also, the elasticity or flexibility of said element will assure positive sealing even though said element may become worn by the abrasive action of the fluid flowing past said element.

The foregoing description of the invention is explanatory thereof and various changes in the size, shape and materials, as well as in the details of the illustrated construction may be made, within the scope of the appended claims, without departing from the spirit of the invention.

of a yieldable material and having its interior and exterior exposed to the pressure exteriorly of the tubing whereby the external and internal pressures acting on the element are equalized, said equalization permitting said member to assume a normal expanded position to close flow through the flow passage, and means for releasing the pressure acting on the interior of said element, whereby the external pressure may distort said element to an open position to allow flow through the passage and into the tubing.

2. A flow device as set forth in claim l, wherein the means for releasing the'pressure acting within the valve element is a pilot valve which is nor- 4rnally closed.

3. A flow device as set forth in claim 1, wherein the means for releasing the pressure acting on the interior of the valve element is a pilot valve which is normally in a closed position, and pressure-actuated means connected with said pilot valve for opening said pilot when the pressure acting thereon attains a predetermined point.

4. A flow device as set forth in claim 1. wherein the hollow valve element ls sleeve-like with one end closed and with its opposite open end secured within the housing..

5. A flow device as set forth in claim 1, together with an auxiliary resilient means confined within -the housing for constantly urging the element toward an expanded position.

6. A flow device including, a well tubing, a housing having communication with the well tubing and having an inlet in its wall, whereby a flow from exteriorly of the tubing through said inlet and housing into the tubing may occur, a flexible valve element adapted to co-act with the inlet to open and close the same, said element sealing the inlet when in an expanded position and allowing now through.the inlet into the housing when ina distorted collapsed position, means for normally equalizing the pressures interiorly and exteriorly of the element' to maintain the element in expanded inlet-closing position, and means actuated by the pressure exteriorly of the tubing for reducing the pressure acting lnteriorly of the valve element whereby external pressure may distort the valve element to inlet-opening position.

7. A flow device as set forth in claim 6, togetherwith auxiliary resilient means confined within the valve element for constantly urging the element to an expanded position to assure closure of the inlet when pressures across said element are equalized.

8. A flow device as set forth in claim 6, wherein the means for reducing the pressure acting interiorly of the valve element is a pilot valve which is opened to permit escape of the pressure within the element.

9. A flow device including, a well tubing, a housing having communication with the well tubing and having an inlet in its wall, whereby a flow from exteriorly of the tubing through said inlet and housing into the tubing may occur, a flexible sleeve-like valve element mounted within the housing and adapted to co-act with the inlet to open and close the same, said element sealing said 10. A now device as set forth. in claim 9, together with auxiliary resilient means ooniined within the valve element for constantly urging said member to an expanded position to assure closure of the inlet when the pressures across the element are equalized.

11. A ow device as set forth in claim 9, wherein the means for reducing the pressure acting interiorly of the valve element is a pilot valve which is opened to permit escape of the pressure within said element.

ROBERT O. WALTON. 

